If the freedom of speech is taken away then dumb and silent we may be led, like sheep to the slaughter.

- George Washington

Friday, 12 February 2010

Running on H

The M4 in south Wales is to become a "hydrogen highway", with alternative energy refuelling points, Welsh Secretary, Peter Hain, has announced. The scheme, to extend into south west England, is aimed at making hydrogen and electric-powered vehicles a viable alternative to petrol-driven machines. Under the plan, Wales will lead in developing alternative fuels, including hydrogen from renewable sources. The aim is to create an extensive renewable refuelling infrastructure.

Now hydrogen power sounds like a great idea. It's completely clean - the only emission is water vapour - and a vehicle running on a hydrogen fuel cell will be quiet and eco-friendly. Just what our lords and masters want for us. But hydrogen has its problems too:

It is very bulky (remember the massive roof-mounted canvas tanks on cars in wartime?), so storage is a problem. To get the energy density of a fuel tank of petrol would need many cubic metres of gas storage: totally impractical, unless you store the hydrogen in a small tank under massive pressure. And the pressure involved would be many thousands of pouns per square inch. Think of the scare stories around LPG tanks in cars, and then multiply it by ten.

It is dangerous; probably more so than petrol. The Hindenburg didn't go up like that because it was made of wood.

Although it is a 'natural' substance, hydrogen isn't free. Getting pure hydrogen involves an input of huge amounts of energy. And where does that energy come from? The bulk of it will be from old coal-fired power stations. So all that hydrogen power does (and the same is true of electric vehicles) is to move the pollution from the vehicle exhaust to the chimney stack of the power station. And making hydrogen is a hugely inefficient process: lots of wasted energy just getting it into the right form to use.

If, and it's a big if, we could produce enough electrical power completely cleanly, then making hydrogen for vehicles might make sense. Replacing all current power stations with nuclear would do it. Wind will never be able to provide the reliable power necessary, and the geography of the UK does not allow any significant production from hydro-electric. But of course Labour's natural antipathy to nuclear has meant that this (even with their welcome late conversion) is not possible in time.

So, go 100% nuclear about 10 years ago, and you stand a fighting chance of hydrogen being a feasible fuel within the next 20 years. As things are, it's just another grand, green gesture.